Mossberg claims the Model 500 is the only shotgun to pass the US Army's Mil-Spec 3443E test, "a brutal and unforgiving torture test with 3,000 rounds of full power 12 gauge buckshot". (The updated 3443G specification requires a metal trigger guard, so only the Model 590A1 variants, which have a heavier barrel and use metal trigger groups instead of the standard Model 500's plastic trigger groups, will fit the requirements.)

While the Marines officially switched to the semi-automatic Benelli M1014 Combat Shotgun in 1999, various branches of the US military are still acquiring pump shotguns. The Navy acquired several thousand Mossberg 590A1 shotguns in 2004, and the US Army placed an order in 2005 for 14,818 units at a price of just over $316 each (The Benelli M1014 is considerably more expensive).

In 2009 US Special Forces Groups procured Military Enhancement Kits to provide a standardized shotgun configuration based on the Mossberg 500. The kits included a collapsible stock, "shotgun retention system", 1913 receiver rail, forend rail system and breaching barrels. A total of 1301 shotguns were converted with the first unit being equipped in July, 2009. The majority of the kits convert the standard issue shotgun to a 14" compact model with a 16" accessory breaching barrel.

Mossberg also produced a US Military version of the model 500. The model number is 500 MILLS and contains a U.S. prefix to the serial number. This particular model (500MILLS) contains all metal parts, is parkerized with a 20" barrel. The magazine capacity is 6+1.

My Infantry Brigade went with a Gov't credit card and purchased all the Mossy 500's they could find in the Miss State area in 2006 prior to going to Afghanistan. These did NOT come from the Gov't purchase pipeline.

Millions. Some you could add up the numbers such as colt, winchester, remington and others by looking them up at http://www.proofhouse.com or other sites to get an approximation. A lot of records are missing or otherwise not available tho. I think it would be a difficult research project.

Mossberg supplied 22 cal training rifles the 44US bolt actions they were marked US Property on the bbl & receivers they also supplied Lend Lease rifle to the Brritts for training. these were in the 42MB model bolt actions. these also were ser number and stamp US Prroperty, many came back home with Britt stampings. and Parker hale receiver sights.
This example has hwat were refered to as sentencing marks. ----- I was teeeeeempeted to remove them but decided to research them first - I found that --
"I would not remove the paint as it is part of the history of the rifle. The daubs are sentencing marks indicating that it was examined and found wanting for something but it was good enough to store pending repair. It could be as simple as a missing sight or it does not have the latest upgrade. The Mossbergs were factory rebuilt in 1948 and fitted with Parker Hale rear sights. Yours may have been scheduled for the upgrade and was surplused out before it could be done" -- so they remain until today ~~MM~~